Life History of the Plain Lacewing

Life History of the Plain Lacewing (Cethosia methypsea methypsea)

Butterfly Biodata:
Genus: Cethosia Fabricius, 1807
Species: methypsea Butler, 1879
Sub-species: methypsea Butler, 1879
Wingspan of Adult Butterfly: 60-80mm
Caterpillar Local Host Plant: A plant in Passifloraceae, with species ID to be confirmed.

Physical Description of Adult Butterfly:

On the upperside, the forewing is black with a white subapical band (broader in the female than in the male) beyond the cell; the basal area is rich orange-red for the male and reddish brown for the female. The hindwing has a black border but is mainly rich orange-red in the male and reddish brown in the female, and there is a series of black spots embedded in the distal margin of the orange-red/reddish-brown area. On the underside, the wings are orange-red (with reddish areas confined to the basal half) with white fasciae adorned with black spots. The forewing cell has several black-edged, pale blue transverse stripes. The wing borders are dark brown and deeply indented with lace-like pattern of white markings. The hindwing has a narrow white submarginal band in addition to the broad, white postdiscal band, both of which are bordered with a series of black spots.

Field Observations of Butterfly Behaviour:

The Plain Lacewing is rarely seen in Singapore and its local occurrence is confined to a small patch of forest in the catchment reserve. Adults have been sighted visiting flowers of flowering plants in forest clearings or alongside forest trails. At times, females can also be seen checking out leaves of its host plant in search of an ovipositing site.

Early Stages:

The local host plant is a vine in the Passifloraceae family and its exact species ID is yet to be determined. It has the distinctive feature of having a variety of leaf shapes and has tendrils which terminate in adhesive pads. Caterpillars of the Plain Lacewing feed on leaves, petiole and stems of the host plant. The Plain Lacewing caterpillars are gregarious throughout all five instars, often eating, resting and moulting together in groups.

Local host plant of the Plain Lacewing, showing the trilobate leaf form.

The eggs of the Plain Lacewing are laid in a moderately large cluster (in teens) on a leaf (underside), a petiole, a young stem or even a tendril. Each egg is pale yellow, barrel-shapped with a ribbed surface. Height: ~1.3mm, diameter of cross section: ~1mm.

A female Plain Lacewing laying eggs on the underside of a leaf.

A cluster of eggs of the Plain Lacewing laid on the petiole of a leaf of the host plant.

A cluster of eggs of the Plain Lacewing laid on the underside of a leaf of the host plant.

Each egg takes about 5-6 days to mature. The young caterpillar nibble away sufficiently large portion of the egg shell to emerge, and typically makes little effort to eat the remnant of the egg shell. The newly hatched has a cylindrical body in yellowish brown, and an initial body length of about 3mm. The body is covered in a grid of tubercles, each with a single long seta. The head is black and there is a pair of short black spines on the first thoracic segment. When feeding, the young caterpillar either skims the lamina on a young leaf or nibbles away at the surface of a young stem.

Two views of a mature egg of the Plain Lacewing.

Two views of a newly hatched caterpillar, length: 3mm.

Two views of a 1st instar caterpillar, late in this stage, length: 4mm.

As the 1st instar caterpillar grows, the body color darkens to orange and finally to wine-red. A faint white saddle mark appears on the 4th abdominal segment initially, but turns prominently white when the caterpillar lies dormant to moult. After 2-2.5 days in the 1st instar and reaching a length of about 5-6mm, the caterpillar moults to the next instar.

A group of 1st instar caterpillars, dormant prior to their moult.

The 2nd instar caterpillar has a dark wine-red body colour, and the rows of tubercles in the 1st instar are replaced by 6 longitudinal rows of dark fine-pointed spines, 3 to each side of the body. The spines in uppermost two rows are the longest. A pair of short and black coronal spine appears on the head. The white saddle is prominently marked. This instar lasts about 2-2.5 days with the body length reaching about 8-9mm before the next moult.

Two views of a group of 2nd instar caterpillars found in a nature reserve.

Two views of a 2nd instar caterpillar, length: 8mm.

The 3rd instar does not bring along any drastic change in physical appearance except for proportionately longer coronal spines (now about the same length as the height of the head capsule), and the larger and more distinct white saddle mark. This instar takes 2-3 days to complete with body length reaching about 15-16mm.

Two views of a 3rd instar caterpillar, early in this stage, length: 10mm.

A group of 3rd instar caterpillars on the underside of a leaf of the host plant.

Two views of a 3rd instar caterpillar, late in this stage, length: 15.5mm.

The coronal spines in the 4th instar caterpillar are again longer proportionately with the length of each spine about equal to the 1.5x height of the head capsule. The spines in the white body segment are now coloured entirely white except for their pointed tips. The upper half of the body is bright scarlet red (especially on the dorsum of 2nd-3rd thoracic segments and 1st, 2nd, 7th-9th abdominal segments), while the lower half is dark wine red. The 4th instar lasts about 2-2.5 days with body length reaching about 22-23mm.

Two views of a newly moulted 4th instar caterpillar.

A group of 4th instar caterpillars almost done with a leaf of the host plant, length: 15mm.

Two views of a 4th instar caterpillar, length: 23mm.

The next moult brings the caterpillar to its 5th and final instar. The caterpillar retains the same body features as in the 4th instar. Now the coronal spines are about 2x the height of the head capsule, and the bright scarlet red dorsal patches appear on almost all body segments. This instar lasts for 3-4 days with the body length reaching up to 32-34mm.

Two views of a newly moulted 5th instar caterpillar, length: 24mm.

A group of early 5th instar caterpillars, nibbling at the tip of a stem.

Two views of a 5th instar caterpillar, length: 32mm.

Toward the end of 5th instar, the caterpillar stops feeding and moves around in search of a pupation site. Finally the caterpillar finds a spot on the underside of a leaf, stalk or stem to spin a silk pad to which it secures itself with the claspers at its posterior end. Now the caterpillar is an immobile pre-pupa, hanging vertically from this pupation site. At times, several pre-pupae could be found in close proximity.

Three pre-pupatory larvae of the Plain Lacewing found on the underside of a leaf.

A group of 3 fresh pupae and a pre-pupa of the Plain Lacewing, on the underside of a leaf.

A Plain Lacewing caterpillar moults to its pupal stage.

Pupation takes place a day later. The pupa hangs vertically. It has two pairs of slender pointed white processes at the middle of its body and a number of less prominent dorsolateral processes. A pair of foliaceous processes adorn the head. Body color is pale brown mottled with white and black patches, and several dorsal spots of silvery/gold colour. Length of pupae: 28-30mm.

Three views of a pupa of the Plain Lacewing. Left: lateral view; Middle: ventral view; Right: dorsal view. After about 6 days of development, the pupa becomes darkened. The next day the adult butterfly emerges to kick-start the around round of the life cycles for this species.

Three views of a mature pupa of the Plain Lacewing.

A Plain Lacewing emerges from its pupal case.

Newly eclosed Plain Lacewing clinging on to its pupal case. References:

• [C&P4] The Butterflies of The Plain Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malaysian Nature Society.
• Butterflies of Thailand, Pisuth Ek-Amnuay, 2nd Edition, 2012
• A Field Guide to the Butterflies of Singapore, Khew S.K., Ink On Paper Communications, 2010.

Text by Horace Tan, Photos by Jerome Chua, Chng CK, Loke PF, Koh Cher Hern, Frederick Ho, Sunny Chir and Horace Tan.

Butterfly of the Month - September 2015

Butterfly of the Month - September 2015
Anderson's Grass Yellow (Eurema andersonii andersonii)

The month of September 2015 will probably go down in Singapore's political history as an exciting month as 2,460,977 voters went to the polls on 11 Sep 2015. For the first time since independence in 1965, all 89 electoral seats were contested. This time around, up for grabs were 16 Group Representation Constituencies and 13 Single Member Constituencies.


An Anderson's Grass Yellow feeding on the flower of the Bandicoot Berry (Leea indica)

It was a very eventful period leading up to Polling Day as each political party held rallies, interviews and podcasts to articulate their manifestos and to persuade the electorate why they should be the voters' representative in Parliament. Social media played a key role, as Singaporeans turned to their favourite cyberspace platforms to read, comment and absorb all the excitement of the once-in-five year hustings.



The incumbent political party, People's Action Party (PAP) won 69.9% of the total valid votes cast - with over a 2/3 majority support from Singaporeans. With all the eligible voters casting their votes for the first time since 1965, this is probably a true reflection of the support from the citizens of Singapore. This is likely to be more representative of the 'silent majority'. Social media, anti-establishment sites and grousing keyboard warriors only form about 30% of the 'alternative voice' supporters (although because of their cyberspace presence, this group appears to give an impression that they represent the majority view). Reality kicks in...



Puddling Anderson's Grass Yellows

On the environmental front, the almost-annual scourge that has become all-familiar with Singaporeans, Malaysians and Indonesians reared its ugly head once again. In the past week, many areas in the 3 countries were shrouded in the choking smog as large tracts of land were razed to the ground in Sumatra and Kalimantan. This yearly affair of clearing forests by burning the land during the dry season appears to have continued despite the Indonesian authorities' warnings to plantation owners.




One wonders how and when this persistent destruction of the land will stop? It is unimaginable that the Indonesian authorities are powerless to prevent this yearly damage. The feeling of helplessness and frustration that Malaysians and Singaporeans feel when the haze descends on us returns year after year with no end in sight. People with respiratory problems or sensitive to the acrid smog in the air will usually have to suffer in silence.


An Anderson's Grass Yellow feeding on the flower of the Mile-a-Minute creeper

The NParks Butterfly Count is ongoing (5-13 Sep) and it will be interesting to see how the haze will affect the numbers and diversity of the butterflies found in our urban parks and gardens. In previous years, when the haze was particularly thick and prolonged, the butterfly population was affected where the numbers dropped significantly.


An Anderson's Grass Yellow feeding on the flower of the Snakeweed (Stachytarpheta indica)

Our Butterfly of the Month for September 2015 is the Anderson's Grass Yellow. This species is one of six Grass Yellows from the genus Eurema found in Singapore. Unlike some of its cousins, the Anderson's Grass Yellow is almost found exclusively in the forested areas. It is moderately common where it occurs in the nature reserves, but cannot be said to be anywhere near the abundance of related species like the Common Grass Yellow and the Three Spot Grass Yellow.



The Anderson's Grass Yellow has a forewing length of about 17-20mm on average. occasionally, very small individuals are observed where the forewing length may drop to about 13-15mm. The species is usually found feeding on flowering plants along the fringes of the nature reserves.



Males of this species are also fond of puddling at sandy streambanks. More often than not, they are encountered singly, unlike the congregations of Common, Three Spot and Chocolate Grass Yellows that are occasionally encountered. They also display a habit of flying and hiding on the underside of a leaf to rest upside down. However, the butterfly is alert and skittish and is not easy to photograph when fluttering around.




The Anderson's Grass Yellow can be separated from the other lookalike Grass Yellows by a single cell spot on the underside of its forewing. There is usually a dark brown sub-apical streak on the forewing (which can sometimes be very indistinct or even absent). The upperside of the butterfly is a rich yellow with black marginal border on both the fore- and hindwings.


A newly-eclosed Anderson's Grass Yellow clinging on to its empty pupal shell

The species has been successfully bred on Ventilago maingayi and Ventilago malaccensis.The host plant is found growing wild in the forested nature reserves of Singapore. The plant is quite unique in that the young leaves of the plant are deep red whilst the mature leaves are green. The caterpillars feed almost exclusively on the young leaves.

Text by Khew SK : Photos by Federick Ho, Khew SK, Jonathan Soong, Simon Sng, Horace Tan, Anthony Wong and Benjamin Yam

Larval Host Plant for Butterflies: Saga Seed Tree

Butterflies' Larval Host Plants #3
The Saga Seed Tree (Adenanthera pavonina )

This 3rd instalment of our Butterflies' Larval Host Plants series features Adenanthera pavonina, a species in Fabaceae (bean family) which is a family of flowering plants known for their nitrogen-fixation ability. With about 18000-old species, Fabaceae is the third largest land plant family, and its members take on a variety of growth forms (trees, shrub, herb, vine, liana). The Saga Seed tree is a perennial member which assumes the tree form.

The Saga Seed tree is native to India and Southern China, but it has been introduced to many countries in the tropics. In Singapore, it is commonly planted in parks/gardens and on roadside for shade and ornamental purposes. It is noteworthy that one particular Saga Seed tree in the Singapore Botanic Garden has even achieved the Heritage Tree Status. Different parts of the Sage Seed tree have been shown to serve useful purposes. For examples, the timber has been used in house and cabinet making, and the wood produces a red dye and used in tonics.

Plant Biodata :
Family:  Fabaceae
Genus:  Adenanthera
Species:  pavonina
Synonyms:  A. gersenii, A. polita, Corallaria parvifolia
Country/Region of Origin:  India, South China
English Common Names:  Saga Seed Tree, Red Sandalwood, Red Bead Tree
Other Local Namezs:  孔雀豆 , 海红豆
Larval Host for Butterfly Species: Plain Nawab, Blue Nawab and  Common Imperial.

Two Saga Seed trees growing on the side of a jogging track in Jurong Lake Park.

A fast growing tree with spreading canopy, the Saga Seed tree can grow up to 20m. It features compound bipinnate leaves. Each leaf is about 10-40cm long with up to 6 pairs of side stalks each of which bearing 9-15 pairs of leaflets. The leaves are shed every 6-8 months, with the leaves turning from green to yellow before dropping off.

Saplings of the Saga Seed tree found alongside a pavement in the Mount Faber Park.

A young leaf in the early stage of growth.

The young developing leaves are yellow to yellowish brown, but turning yellowish green to dark green when they   mature. The young leaves are edible, and have been used with the bark to make a decoction in traditional medicine for treatment of diarrhoea.

Two side stalks of leaflets, with the lower one fully matured.

Mature leaves of the Sa.

Flowers of the Saga Seed Tree are small and creamy yellow. They occur in dense clusters on long stalks (8-12cm long). These flowers are faintly scented and turn dull orange when they age.

Stalks of flower buds of the Saga Seed Tree.

Stalks of flowers and flower buds of the Saga Seed Tree.

Close up views of a stalk of flower bud (left); flowers (centre, right).

Close up view of young flowers.

Close up view of individual flowers.

The fruits occur in long (10-20cm), curved pods. As a pod develops, bulges corresponding to the location of seeds grow in size. The pod turns brown when it is ripened, and it then splits open in two twisted halves to reveal the scarlet seeds. Each seed is hard and near heart-shaped. The ripened pods will eventually fall and litter the ground below the tree. Cooked seeds are edible although the raw seeds are toxic. The seeds have many other uses including being used as beads in jewellery (as beads),  as  industrial lubricants (oil extracts from seed), as unit of weights in ancient India and even as symbols of love in China (Chinese name: 相思豆).

Young fruits of the Saga Seed Tree with the bulges barely noticeable.

Fully developed pods of the Saga Seed Tree.

Ripened pods still attached to the mother tree.

Close-up view of a ripened pod fallen to the ground.

Close-up view of a seed of the Saga Seed Tree.

In Singapore, the Saga Seed tree also serves as the larval host plant for three butterfly species: Plain Nawab, Blue Nawab and  Common Imperial. The first two are Charaxinae (a nymphalid subfamily) species, while the last one is a lycaenid.

A Plain Nawab butterfly.

A Blue Nawab butterfly.

A Common Imperial butterfly.

Eggs of these three butterfly species are typically laid by the mother butterfly on the stem/leaves of a young plant of the Saga Seed Tree at low heights (knee height to chest level). The eggs of the two Nawab species are mostly found laid on the upperside of a leaflet, with a few on the underside.

A female Plain Nawab laying an egg on the underside of a leaflet of the Saga Seed Tree.

An egg of the Plain Nawab found a leaflet of the Saga Seed Tree.

Eggs of the Blue Nawab found on the upperside of leaflets.

Caterpillars of all three species feed   on leaflets of the Saga Seed Tree.  The two Nawab species have the habit of  building a "base camp" made from weaving several adjacent leaflets together.

A late penultimate instar instar caterpillar of the Plain Nawab resting in its base camp on a Sage Seed Tree in the Mount Faber Park.

An early 5th instar caterpillar of the Blue Nawab found alongside a park connector track in the west.

A final instar caterpillar of the Plain Nawab in its base camp found in the Telok Blangah Hill Park.

A final instar caterpillar of the Blue Nawab in its base camp found in the west.

Caterpillars of the two Nawab species typically pupate on the same Saga Seed Tree they have been feeding on. The pupation site is usually the underside of a stem or the rachis of a compound leaf. Likewise for Common Imperial, the pupation site is usually a spot on the stem of the same plant it feeds on.

A pupa of the Blue Nawab found in the vicinity of the Chinese Garden.

A pupa of the Plain Nawab found in the Dairy Farm Nature Park.

If you happen to encounter a young Saga Seed tree in your next outing in the field, try to look for the odd sight of a few leaflets weaved together. If you do find one, chances are you have found the base camp of a Nawab caterpillar and even the caterpillar itself. The most striking feature of Nawab caterpillars is their dragon-like head, hence it would be rather easy for you to know that you have found the real McCoy.

References:

• The Concise Flora of Singapore : Hsuan Keng Singapore University Press, 1990.
• 1001 Garden Plants in Singapore : Boo Chih Min, Kartini Omar-Hor and Ou-Yang Chow Lin, National Parks Board, 2nd Edition 2007.
• Saga Tree - WideSingapore Blog.
• Saga Seed Tree, Naturia web site.
• Adenanthera pavonina, Wikipedia.

Text and Photos by Horace Tan.